1. Field of the Invention
This invention relates to rotary lawn mowers, and more particularly to an improved rotary lawn mower including a housing having a mulching liner, and to an improved mulching liner for rotary lawn mowers.
2. Description of the Prior Art
In the past, the majority of rotary lawn mowers have been of the type having a discharge chute formed either in the downwardly depending side wall or skirt of the mower housing or in the peripheral edge portion of the housing top wall, or both, for discharging the clippings. The configuration of the housing and of the rotary cutter blade were such as to create a relatively high-velocity air flow from beneath the housing to entrain the clippings and to discharge them with sufficient velocity either to deposit the clippings in a bag carried on or behind the mower, or to distribute the clippings some distance from the mower. Such mowers are sometimes hereinafter referred to generally as bagging mowers whether or not the mower employs a clippings bag.
Lawn mowers are also known in which the housing has no top or peripheral discharge chute so that the clippings are deposited back onto the lawn beneath the housing as the mower progresses along its path. Such mowers are generally known as mulching mowers and are designed to disintegrate or chop the clippings as finely as possible to enable them to more readily sift downward through the standing grass to the ground so that raking is not required. Once the finely chopped clippings reach the ground, they quickly decompose, or mulch, providing natural fertilizer for the growing plants. Such mulching mowers eliminate the well-known and troublesome problem of disposing of grass clippings collected in the bag of a conventional mower, or raked-up following mowing when a bag is not used.
While there are both economic and ecological reasons for mulching and returning grass clippings to the ground, there are times when it is inconvenient or undesirable to do so. For example, when grass is unusually high and thick, as after a prolonged rainy season, or when the grass has not been mowed for an extended period, the quantity of clippings may be too great to sift through to the ground. Also, in periods of extremely fast growth such as in the spring, the accumulation of mulch on the ground can be so rapid as to build up to the point of choking out new grass plants, or to create conditions favorable to harmful insects or disease. Thus, it may be desirable to collect the clippings at times and to mulch them at other times.
Various attempts have been made in the past to convert conventional rotary lawn mowers to mulching mowers as, for example, by providing means for covering or blocking the discharge chute in the mower housing. However, these attempts have not been entirely successful since the housing of bagging mowers are conventionally designed to create maximum air velocity within the housing to facilitate discharge of the clippings. Blocking the discharge chute of such mowers does not result in effective mulching but rather tends to clog the mower housing and to leave the clippings in unsightly clumps deposited on top of the standing grass.
It also has been proposed to convert a bagging mower to a mulching mower by the use of removable cutter blades or the like mounted within the mower housing, and one such device is illustrated in U.S. Pat. No. 3,797,214. However, this patent teaches that the conventional clipping discharge chute should be provided so that the clippings, which are chopped on the sharp edges of the fixed blades within the housing, are then discharged and distributed via the chute. Such devices have a tendency to clog and generally are ineffective.
The various attempts to convert conventional bagging type lawn mowers to mulching mowers have not met with widespread acceptance with the result that the average homeowner must take a choice between a bagging mower and a mulching mower, or alternatively to buy one of each.
In view of the above it is a primary object of the present invention to provide an improved lawn mowing apparatus which is readily convertible between a conventional bagging mower and an effective mulching mower.
Another object of the invention is to provide such a mowing apparatus which can be readily and easily converted between a bagging and a mulching mower by unskilled persons and without requiring special tools.
Another object of the invention is to provide an improved mulching attachment for a bagging type lawn mower, which attachment will provide effective mulching and efficient distribution of the mulched clippings with a minimum of clogging of the mowing apparatus.
A further object is to provide an improved lawn mower having a rigid mower housing and an improved mulching liner mounted beneath the housing for directing grass clippings inwardly from the periphery of the housing and downwardly through the plane of the rotating blade.